23.07.2026

Back to a hothouse earth

Jack Conrad reviews Bill McGuire The fate of the world: a history and future of the climate crisis Harper Collins, 2026, pp265, £20

A couple of years back, in 2024, climate scientists recorded, for the first time, global temperatures exceeding 1.5°C above preindustrial levels. The average figure was 1.6°C. The following year, 2025, was 1.47°C above preindustrial levels - the third warmest on record.¹ However, while 2026 is expected to be roughly the same as 2025, climate models suggest 2027 could well bring even higher temperatures because of the El Niño effect.²

Given the sheer momentum of the rise, 2°C+ seems a distinct possibility in the early 2030s, not least with Donald Trump, America pulling out of the Paris agreement and the ‘drill, baby, drill’ message to big oil.

But it is not only the good old US of A. The world continues to giddily pump out greenhouse gases on an increasing scale. Indeed there are serious warnings that with atmospheric CO₂ concentrations going from 280 parts per million in preindustrial times to 430ppm today³, climate feedback will kick in soon and catapult temperatures to 3°C, 4°C and beyond. Enough, it is authoritatively reckoned, to bring about “civilisational collapse” some time between 2070 and 90.⁴ This is within the lifetime of our younger readers.

Here is what the solemn pledges to limit global temperature increases to well below 2°C (ideally to 1.5°C), made in Paris 2015, have come to.

Grand scale

Against this grim background, Bill McGuire - emeritus professor of climate hazard at University College London - has written his much acclaimed book: it comes with glowing recommendations from the great and good, when it comes to the climate crisis (Chris Packham, Tony Juniper, Jonathan Porret, Roger Hallam, etc).

His is a popular book, designed to inform the widest audience, but also rouse. Basically, the thesis is that, with the industrial revolution, humanity has broken the planet’s recent (in geological terms) interglacial oscillation between cool and the cold. Without the post-1850 massive release of CO₂ and other greenhouse gases we would expect a gradual warming of temperatures before returning to the ice age conditions of some 10-15,000 years ago. Instead our future lies in a hotter - perhaps a much hotter - past.

Professor McGuire begins at the beginning with our ever changing star, the sun - one of 100 billion stars in our galaxy, the Milky Way. Yet, while this fusion reactor is the “ultimate arbiter of the temperature of our world”, there are other factors too (p2).

Planet Earth dates back some 4.6 billion years to the formation of the solar system out of the primordial dust left over from prior stellar extinctions. Crucially, though, the “head-on collision” with Theia, a Mars sized “chunk of rock”, not only added to the Earth’s mass: it created an oversized satellite, the moon, which orbits and still churns the planet. This has had “huge consequences for our climate” (p5). Without the moon, no axial tilt, no seasons and no tides.

The Earth’s first eon, the Hadean - named after Hades - saw the molten surface slowly cool, over some five million years, and harden into a solid crust (p27). The first atmosphere contained abundant amounts of CO₂ - perhaps between 10 and 200 times as much as today.⁵ Solar winds stripped away the lighter, volatile gases. Because of the much closer proximity of the moon compared with today, together with associated volcanic activity and countless asteroid and meteorite strikes, a second atmosphere formed: besides CO₂ there was ammonia, methane, carbon monoxide and water.

Earth was a hothouse - more like present-day Venus than present-day Mars. Surface temperatures were a melting 230°C. Despite that, there were oceans. Heavy atmospheric pressure - maybe up to 100 bar - prevented liquid water evaporating into steam⁶: to put it mildly, not a “nice place to be” (p6).

Amazingly, there is “some evidence” of life’s “arrival” as long ago as 4.1 billion years (p27). True, the building blocks could have arrived from asteroids and meteorites. Either way, abiotic processing of CHNO compounds resulted in prebiotic compounds. Certainly, as shown by the fossil record, simple, heterotrophic (food-eating) life was abundant some 3.1 billion years ago: tiny, single-cell, blue-green algae were busy converting carbon dioxide into oxygen through photosynthesis. Eventually there was enough oxygen in the atmosphere to react with the methane and turn the sky blue.⁷ So Earth’s third atmosphere is the product of co-evolution. Indeed our climate results from the interaction of atmosphere, hydrosphere, lithosphere … and biosphere.

The ozone layer formed 600 million years ago … and as a byproduct it provides the vital shielding from the sun’s biologically harmful ultraviolet rays. The evolutionary leap into complex life forms happened in the balmy seas of some 540 million years ago. The Cambrian explosion occupies a mere few million years - in geological terms, a blink of the eye - and led to “virtually all major groups of modern animals”.⁸

Temperatures in the deep past were mostly much higher than today. The Cambrian (600-500 million years ago) 14°C hotter. The Silurian (425-405 million years ago) 4°C hotter. The Devonian (405-345 million years ago) 10°C hotter. The Triassic (252-201 million years ago) 10°C hotter. The Jurassic (201-145 million years ago) 8°C hotter. The Cretaceous (145-66 million years ago) 4°C hotter. The Palaeocene (66-55 million years ago) 10°C hotter. The Eocene (55-33 million years ago) 4.5°C to 12°C hotter.

Besides hothouse Earths - the default condition - there have been, though, iceball Earths: eg, the Permian (298-252 million years ago). It was on average 3°C colder than today. As might easily be guessed, all my figures are rough and ready estimates, but they serve, nonetheless, to illustrate the deep past.⁹

Professor McGuire explains that ‘hothouse’ describes conditions where things are not just warmer, but where the “poles are ice free”: therefore sea levels are much higher (p24). Conversely icehouse conditions see relatively reduced levels of greenhouse gases, much lower sea levels and massive extended ice-sheets. His fear is, of course, that we are sleepwalking back into the past at an extraordinarily rapid pace - back, for example, to the sweltering Eocene.

Professor McGuire treats the Eocene as our probable future (unless there is an immediate and radical change of direction). During this epoch there were palm trees in Antarctica, great forests covered northern Canada, Siberia and even parts of Greenland - home to three-toed horses and herds of giant camels (p39). Charcoal and soot layers in the geological record reveal “huge wildfires”. There is the distinct possibility too that hurricanes and typhoons reached enormous speeds and persisted for months on end. As for sea levels, they were 100 to 150 metres higher than today.

Doubtless, some of these temperature changes we have seen across the Earth’s natural history are due to planetary wobbles (Milankovitch cycles), volcanic activity and variations in solar brightness. But there is also plate tectonics: the continents ‘drift’ at the speed with which your fingernails grow.

Some three billion years ago the vast mass of the Earth’s surface seems to have been covered with water. There were only a few spots of dry land. Arctica, or Arctida, was perhaps the first supercontinent, and arose some 2.5 billion years ago (there might well have been others, but, if so, only mere geological fragments remain). Eventually Arctica broke apart, but after many more millions of years there were other succeeding continents and supercontinents: Kenorland, Columbia, Rodinia, Pannonia.

Beginning in the Neoproterzoic, about 550 million years ago, most of Earth’s land masses are found joined together in the Gondwana supercontinent: McGuire writes of a supercontinent cycle and how it has a “profound impact on all sorts of geological mechanisms” - not least those which relate to “atmospheric carbon levels” (p48). Basically, high carbon levels coincide with the coming together and consolidation of supercontinents; lower carbon levels with when they break apart.

There is life too. With the conditions brought about by the Gondwana supercontinent, things were ripe for terrestrial flora and fauna. Probably the migration from the seas began some 500 million years ago.¹⁰ Complex life drifted, crept, coiled, clambered and slithered onto the land and rapidly evolved.

Something like our present configuration of continents appeared 60 million years ago. Doubtless this helped establish our contemporary algific - ie, chilling - climate regime. The North American and Eurasian land masses more or less encircle the northern pole; that, and the Antarctic continental plate centred on the southern pole, provide almost perfect conditions for ensuring an oscillation between cool and cold conditions. Moreover, the bulk of Earth’s fresh water is kept frozen in two gigantic polar ice sheets - which means much reduced sea levels.

Over the last million years there has been a glacial-interglacial, 100,000-year pattern. Each cycle has its own particular features and oddities. Understandably, though, as with any study of the past, data becomes ever more uncertain with increasing distances of time. So the best records we possess go from the interglacial (known as the Eemian) period down to the present Holocene period - deep ice cores drilled from Greenland and Antarctica have yielded enormous amounts of information.

In terms of climatic transition, the most reliable information is for what is called the Younger Dryas to Holocene, which ended the last ice age. At its maximum, some 15,000 to 20,000 years ago, the Arctic ice sheet extended all the way down to Chicago, New York, Moscow and London and saw much lower sea levels than today. What is now Britain was joined to France, the Netherlands and Denmark. Recent studies give a -6.1°C average temperature.¹¹

The transition to our present-day climate regime occurred some 11,650 years ago and saw the retreat of the great ice sheets. The tipping point seems to have been only a decade or two long. It is argued that the “speed of this change is probably representative of similar, but less well-studied, climate transitions during the last few hundred thousand years”.¹² In point of fact, says McGuire, any complex system, such as the climate, is “prone to tipping” (p120).

During the present (Holocene) interglacial period, there have been cold and dry phases occurring over a roughly 1,500-year cycle, and climate transitions on a decade-to-century timescale. There have been little ice ages, as well as bursts of relative warmth. Between 1100 and 1300, for example, Europe experienced temperatures which were 0.7°C to 1.6°C higher than today (though, it must be emphasised, this was a local, not a global, phenomenon: elsewhere things were cooler). That allowed for more productive agriculture throughout the continent and saw flourishing English vineyards.

It is also worth recalling, though, that the Thames regularly froze solid during mid-17th century winters and that the years from 1805 to 1820 were comparably cold and bleak. What we are experiencing at present certainly needs to be put into the context of the transition from the little ice age, which finally ended around 1880. Temperatures would be expected to rise … very slightly. But, of course, what we have seen is way beyond that: temperatures increased on average by 0.08°C every decade since 1880 and by an average 0.18°C since 1981.¹³ The main cause is human-induced greenhouse gases: eg, in the 20th and 21st centuries “the level of carbon dioxide rose by 40%” - now the highest for some 20 million years (UK Met Office).¹⁴

McGuire is withering, when it comes to so-called climate sceptics, such as Piers Corbyn. The same goes for “pragmatic politicians” who admit the dangers of runaway global warming, but refuse to do anything meaningful, because of electoral considerations, media spin, cost, etc. However, showing something approaching resignation, he despairingly says that, for “good or ill”, we are ultimately “in the hands of politicians and global corporations” (p220).

Well, Bill, if today’s mainstream bourgeois politicians stay in control and continue to serve the global corporations, it will certainly be for the ill. Perhaps triggering, as already mentioned, civilisational breakdown and, as McGuire argues, the “likely splintering of effective central control” - something which he almost relishes, because it will, in his opinion, force a social reset and provide an “opportunity for a long, hard think about where we went wrong and what we can do differently - and better - next time” (p223).

Here is a real flaw in what is otherwise an excellent book. Though McGuire bemoans “consumer capitalism”, he is, in the absence of a viable counterpower, reduced to almost accepting the ‘inevitable’ and advocating small-scale solutions, like adapting your house and reaching out to neighbours at a “local level, meaning town, village, street, block of flats” (p223). Nothing wrong with such solutions in and of themselves. of course. But, given that we face a global climate crisis that threatens social breakdown, clearly inadequate.

Politics needed

To get an idea of the political problems we face when it comes to convincing the likes of Bill McGuire, we need look no further than the Socialist Workers Party. We shall leave aside here the notorious ‘What we stand for’ formulation found in Socialist Worker that was unquestioningly trotted out week after week and year after year: “Workers create all wealth under capitalism” (proposition 1). As I show in The little red climate-book (2023), a Lassallean, not a Marxist formulation.¹⁵ No less to the point, nature is, in fact, the main source of wealth, no matter what the mode of production.

Instead, we shall look at the SWP’s front, the oddly named Campaign against Climate Change. Why ‘oddly named’? Simply because, given the potted history of Earth’s climate outlined above, let alone professor McGuire’s much more detailed account, it reveals a profound ignorance of what should be ABC, when it comes to the climate.

The climate has and will continue to change. In fact, climate and change go together like weather and change. The two are inseparable. The weather changes from hour to hour, day to day and month to month. Imagine a Campaign against Weather Change. It would be too, too silly.

But the problem runs deeper, far deeper. Despite being promoted by the SWP, CCC, founded in 2001, is politically safe, soggy and, quite frankly, stupid. Capitalism, socialism, the working class all go studiedly unmentioned.

According to its ‘mission statement’, CCC exists to “influence those with the greatest power” to “minimise” the “harmful effects of climate change” with the “utmost speed and resolution”. Flattering courtiers similarly pleaded to Canute, the 11th century king of Norway, Denmark and England, to reverse the incoming tide. Needless to say, as he famously showed (purportedly on Thorney Island), no-one, not even he, could pull off such a feat.

Nor, despite CCC “street demonstrations” and avoidance of “detailed questions” in the attempt to “bring together as many people as possible”, can we really expect “those with the greatest power” to agree an “international climate treaty” that will actually “minimise” the “harmful effects of climate change”.¹⁶

Well, of course, since that ‘mission statement’ was first written, an “international climate treaty” has been agreed. With much fanfare, Cop21 was adopted on December 12 2015 in Paris, signed on April 22 2016 by 195 parties and supposedly made effective on November 4 2016. But has this international climate treaty really served to “minimise” the “harmful effects of climate change”? Hardly: emissions continued to rise.¹⁷

Surely then, to “minimise” those “harmful effects” our sights must be set far higher than “street demonstrations” (or elitist stunts). We must talk about capitalism. We must talk about socialism. We must talk about organising the working class into the ruling class. The CCC ‘mission statement’ needs more than a long overdue update. No, an entirely different approach is needed.

Climate is big weather. Karen Bice gives the following definition: climate “is simply weather ‘averaged’ over a time period of one year or more”.¹⁸ In other words, there is nothing fixed about the climate. Climate change has never ceased, is ongoing and must therefore be considered natural. Notions of a static, an unchanging climate are, to put it mildly, badly misconceived. While the climate constantly undergoes change, that happens within a self-adjusting system: that is, within a relatively stable equilibrium, and hence distinct geological epochs and periods. However, yes, there are tipping points - often accompanied by mass extinctions. There have indeed been five great mass extinctions: the first happening at the end of the Ordovician period 445 million years ago.

McGuire usefully devotes an entire chapter to this: ‘Endings, close calls and new beginnings’ (pp153-77). “Ultimately”, he says, a species, either “evolves into something else or succumbs to some kind of external threat”. Checking the famous Doomsday Clock, he soberly warns that we stand 85 seconds away from extinction.

Most species last between 500,000 and three million years. Homo sapiens have only been around for some 300,000 years, so we are comparative youngsters and might expect to last many thousands of years more. Maybe millions. However, we are not a ‘normal’ species. Though we continue to evolve, straightforward evolution no longer applies. The danger we face is not from nature in the sense of being red in tooth and claw. Leave aside a generalised nuclear exchange, the main danger we face is from our own grossly irresponsible actions - well, the grossly irresponsible actions of a system which has no choice but to accumulate for the sake of accumulation.

So the reason why we face the danger of a “hothouse hell” is surely all too obvious: M-C-M'. Under capitalism, money is laid out for the production of commodities with one overriding aim: making more money (ie, profit) - the secret of making something out of nothing lying in the exploitation of labour-power. Surplus value is pumped out from workers and realised through market sale. Using money to make more money is, though, a never-ending imperative. Hence what is called the Capitalocene (p191).

And yet we have also seen the Soviet Union of the five-year plans and a non-capitalist system of accumulation for the sake of accumulation. There is China too. Today it is the world’s biggest emitter of greenhouse gases. True, as a country, it is fully integrated into the global capitalist economy, but, on the other hand, it is dominated by the Communist Party of China, where, at least arguably, politics is in command. Exactly the sort of hybrid regime Marxists would predict in our epochal transition from the capitalist to the communist mode of production.

Climate socialism

It is also worth questioning McGuire’s assumption that, with the climate crisis, the centralised state will be “splintered”. Not that we should discount that possibility. But if it happens what will arise will not be a multitude of peaceful towns, villages and hamlets happily rubbing alongside each other in their climate-adapted houses and flats. On the contrary, the likelihood would be warlordism and social chaos. Eg, the collapse of the western Roman empire saw rival generals and tribal leaders fighting over the wreckage and in some areas - eg, Brittania - severe social and technological retrogression. Christianity, building in stone, using kiln-baked roofing tiles, minting coins, even writing virtually disappeared.¹⁹

But there is another possibility. The centralised state can impose itself over capitalist society and suppress - or even supersede - the law of value in the interests of the state as the state. For many on the left, not unreasonably, capitalism is defined as categorically “incapable of carrying out the radical measures required”.²⁰ “Capitalism can’t solve the climate crisis.”²¹ “Can this climate emergency be halted under the current world economic, political and social system - capitalism? … No.”²²

However, even the most fabulously wealthy billionaires and the system’s top politicians and state actors live on the same planet as the rest of us (true, Elon Musk wants to rocket off to a frigid, lifeless, almost airless Mars, but he is widely considered to be bonkers by his more sober-minded peers). Even if it is only in the interests of their children and grandchildren, they know that something must be done, and done soon … that or we collectively face Doomsday. True, according to the writer and high-class prostitute known as Salome - she served the needs of the rich and powerful at the Davos conferences - many of them think we are in the end days and that they might as well enjoy themselves to absolute excess while they can.²³

So it is hard to imagine today that any of the big countries will carry out a programme that actually achieves net-zero emissions by 2030 or 2035 - after all, that would require a dramatic restructuring of the entire socio-economic order. Therefore, in all probability, today’s crop of myopic, lying, narrow-minded, thoroughly corrupt establishment politicians will continue with their denialism - that or simply kicking decisive action down the road to an electorally safe distant future. Meantime there will be more drilling for oil and gas, more nuclear power plants, more roads, more air travel, more poor-quality housing … crucially, more of everything - ie, more economic growth for the sake of economic growth.

Yet, as seen with the Covid pandemic - and World War II and World War I before that - the ruling class was prepared to allow governments to temporarily suspend the law of value, given a dire emergency. The normal workings of capitalism were overridden, curtailed or tightly directed in order to achieve agreed state aims.

The more intelligent sections of the left have written about how governments introduced ‘Covid socialism’ - roughly equivalent to the Kriegssozialismus (war socialism) put into effect by the German high command in 1916: ie, the use of concentrated state power to deal with a dire national emergency - the Oxford AstraZeneca vaccine being a good example. Developed double quick, produced on a non-profit basis, it was then rolled out and administered according to need by the NHS.

In terms of the general interest - more particularly the general capitalist interest - governments will take what are usually regarded as extreme measures. Faced with Covid-19, then Tory chancellor Rishi Sunak talked about tearing up his economic textbooks, doing what is necessary, thinking the unthinkable, and so on and so forth.

Though fraught with horrendous difficulties, not least because capitalism - from the level of the firm to that of the state - is characterised by internally generated contradictions, we should not categorically discount the possibility that this will happen with the climate crisis.

So ‘climate socialism’ imposed by a firefighter state - maybe urged on by Friends of the Earth, the Green Party and CCC demands for the declaration of a ‘climate emergency’; maybe with ‘beyond politics’ green advisors, enlightened technocrats, the securocracy and the armed forces playing a leading role - could conceivably impose draconian restrictions on greenhouse gas emissions by reorganising industry, transport, housing and agriculture.

Of course, that - or something like it - would have to happen in all the major countries, if the rise in global warming is to be limited to 2°C (1.5°C is now a dead letter). Adding to that little difficulty, the imperial hegemon, the United States, is in visible decline and is, as a result, bent on destruction and extracting ever more tribute - not the construction that marked out the post-1945 world order with the Marshall Plan, Bretton Woods and the social democratic consensus. So there is nowadays no effective power that can enforce the general good.

Even on a purely national level, we should have no illusions about any climate socialism, introduced, overseen and enforced by this or that capitalist state (or, for that matter, China’s hybrid regime). As with war socialism, if climate socialism happens, there will be stupid blunders, severe restrictions on democratic rights, attempts to drive down popular living standards - all accompanied by massive corruption and corresponding opportunities for well-connected insiders to enrich themselves beyond the dreams of Croesus.

Nor will such a climate socialism evolve peacefully and smoothly into proletarian socialism. True, we reach a partial negation of capitalist production - the outer limits of capitalist society. But, because there is a swollen, parasitic, aggressively repressive, bureaucratic state, what we have is the extreme opposite of proletarian socialism.

Nonetheless, there is a relationship between climate socialism - in reality capitalism attempting to save itself on the back of the working class - and proletarian socialism. After all, in the paragraph above - the one talking about draconian restrictions on greenhouse gas emissions and reorganising industry, transport, housing and agriculture - substitute the firefighter state with one where the working class is organised as the state power.

Such a state, based on extreme democracy, closely coordinating with other similar states across the globe, could radically reorganise power generation, industry, agriculture, transport and housing; a state that reduces greenhouse gas emissions to net zero and then below; a state that subordinates production to need. Then it is clear that such a state is nothing other than genuine climate socialism that really does benefit the whole of humanity - and therefore represents the negation of capitalism and the first step towards a classless, moneyless, stateless and ecologically sustainable communism.

This, not localism, not accepting the inevitability of 3°C … and beyond, as some sort of blessing in disguise, provides the only rational basis for building “a new global community” that can “live sustainably as custodians of the natural world rather than its plunderers” (p223).

Jack Conrad

1. climate.copernicus.eu/rapid-approach-15degc-global-warming-threshold-paris-agreement.↩︎

2. www.carbonbrief.org/state-of-the-climate-strong-el-nino-puts-2026-on-track-for-second-warmest-year.↩︎

3. www.co2.earth/daily-co2. The same source considers the ‘safe’ level be around 350ppm (ppm = parts per million).↩︎

4. actuaries.org.uk/news-and-media-releases/news-articles/2025/jan/16-jan-25-planetary-solvency-finding-our-balance-with-nature.↩︎

5. sciencing.com/earths-first-atmosphere-contained-gases-2034.html.↩︎

6. Atmospheric pressure is measured according to a bar unit. At sea level the average atmospheric pressure on Earth today is roughly 1.013 bar and on Venus around 90 bar. See pubsapp.acs.org/subscribe/archive/ci/30/i12/html/12learn.html.↩︎

7. forces.si.edu/atmosphere/02_02_03.html.↩︎

8. SJ Gould Wonderful life: the Burgess shale and the nature of history London 1990, p24.↩︎

9. en.wikipedia.org/wiki/Geologic_temperature_record#/media/File:All_ palaeotemps.svg.↩︎

10. www.nhm.ac.uk/discover/news/2018/february/plant-life-on-earth-is-mucholder-than-we-thought.html.↩︎

11. www.nature.com/articles/s41586-020-2617-x.↩︎

12. J Adams, M Maslim and E Thomas, ‘Sudden climate transition during the Quaternary’ Progress in Physical Geography March 1999: See - www.researchgate.net/publication/247670427_Sudden_climate_transitions_during_the_Quaternary.↩︎

13. www.climate.gov/news-features/understanding-climate/climate-change-global-temperature.↩︎

14. www.metoffice.gov.uk/weather/climate-change/causes-of-climate-change.↩︎

15. J Conrad The little red climate-book London 2023, pp17-26.↩︎

16. www.campaigncc.org/aboutus/missionstatement.↩︎

17. oilprice.com/The-Environment/Global-Warming/Carbon-Emissions-OnTrack-To-Reach-An-All-Time-High.html.↩︎

18. web.archive.org/web/20070621060432/www.beloit.edu/~SEPM/Earth_Works/Plate_Movements.html.↩︎

19. C Wickham The inheritance of Rome: a history of Europe from 400 to 1000 London 2010.↩︎

20. Socialist Appeal September 2019.↩︎

21. Socialist Worker March 27 2019.↩︎

22. The Socialist September 15 2021.↩︎

23. www.facebook.com/WIONews/posts/prostitution-and-hush-money-what-happens-behind-the-closed-doors-of-davos-world-/1242292631343242.↩︎